CN112352471A

CN112352471A - Lighting system

Info

Publication number: CN112352471A
Application number: CN201980043132.3A
Authority: CN
Inventors: M·C·J·M·维森伯格; L·L·D·范德坡; M·P·克鲁森
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2018-06-25
Filing date: 2019-06-20
Publication date: 2021-02-09
Anticipated expiration: 2039-06-20
Also published as: US20210215324A1; CN112352471B; WO2020002123A1; US11350773B2; EP3811740A1

Abstract

The invention relates to a lighting device, a lighting system and a lighting method. The lighting device comprises a row of lighting units mounted on an elongated carrier in a first direction X, wherein each lighting unit is mounted in a respective fixed unique predetermined orientation. The illumination device is configured to project a line of spots directly on a target plane P, the plane P extending in the first direction X and in a second direction Y transverse to the first direction. The row of light spots extends in a second direction and wherein the illumination device is offset from the plane P in a third direction Z. The lighting system comprises at least a first and at least a second lighting device substantially in a line in the length direction. Alternatively, the first and at least one second lighting device may extend in parallel in two or three rows. The lighting system further optionally comprises a control unit for individually controlling/addressing the lighting units of at least the first and further lighting devices.

Description

Lighting system

Technical Field

The present invention relates to a lighting system.

Background

It is known from research that setting the lighting in a shop window scene by means of known lighting devices and lighting systems is often considered a nuisance by shop personnel or visual vendors who have to decorate and illuminate. It generally involves a number of disadvantages:

(1) space in the shop window is often limited, since most of the space is occupied by the displayed models and products. Therefore, standing in the shop window is risky, and small errors moving around can cause the entire scene to be disturbed.

(2) Another disadvantage is that spotlights for shop window lighting are often mounted in high positions, out of reach, which means that ladders are needed to aim the spotlights. This also carries the risk of disturbing the scene and the risk of falls which can lead to injury to store personnel.

(3) In addition to the limited space, the (modeled) result of the illumination (effect of light and shadow) due to the position and aiming of the spot light cannot be judged, because the person doing this is too close to the scene to see the visual end result (as a whole), as can be seen from the street. For best results, one person should stand outside the front of the shop window and instruct others to perfectly position and aim the spotlights to make the desired lighting scene.

(4) Furthermore, there is a problem of over-lighting or under-lighting of the scene. During the day, light must be shone onto the scene at a high intensity to reduce disturbing reflections in the shop window glass due to daylight (reflected from the opposite surface). Typically, this is done by using a narrow beam spot light with high intensity to increase the brightness on the display. However, depending on time, season and weather conditions, the lighting level may vary greatly. Therefore, the lighting level is typically installed to operate in the most difficult lighting situation (hence the high white daylight level measured in clear sky at 12.00 summer). This causes the display to be generally over-illuminated (when daylight conditions are low) and this consumes a lot of energy. At night, this is not needed and only a small amount of light is needed to create a more balanced and beautiful lighting scene, thereby improving the display quality and saving energy at the same time. In practice, it is often found that the same lighting solution is used for all weather (24/7).

Note that the same system can also be used in stores for wall and other display settings. The comments here are essentially the same (space, ladder, location to view the scene from a distance to see the lighting effect).

(5) Most solutions in current shop windows are static. It is known from research that the human eye is very sensitive to both brightness and movement. Typically, scenes with moving light cannot be made unless movable spotlights are used. This can only be done by means of a programmable electric spotlight product. For example, it is known to have track lighting systems with multiple motors for translating, zooming, tilting, and moving the light along the track. The disadvantage is that dynamic (mechanically moving) products are more sensitive to failure and maintenance than static products.

(6) For a more realistic/natural and attractive presentation, it is preferred to use two different color temperatures and spotlights with different beam angles aimed from different positions. Like in daylight under outdoor conditions, skylight scattered by clouds is generally not directional and is cooler than directional sunlight. To mimic this effect, narrow-beam spotlights with a lower color temperature (warmer looking) are usually used from one side (in the profession, these are called main lights (they mimic the directional sun beam)) and wider-beam spotlights with a higher color temperature (cooler looking) are used from the other side to fill in the (too hard) shadows (in the profession, these are called fill lights). In general, it is preferable to arrange the main lamp and the supplementary lighting lamp from opposite sides at a horizontal angle of 45 degrees and at an angle of 30 degrees to the vertical in the vertical direction, so-called "main/supplementary lighting spotlight". Many people in shop window displays are unaware of these effects and there are often no variety of spot lights in the shop that are on the spot.

(7) In addition to the main light spot and the supplementary light spot, it is also good to add a backlight effect. In practice, this is not usually done.

(8) In order to cooperate with a backlight, a thin beam or an upward-illuminating spotlight is also used. This is a spotlight which is usually mounted at the bottom in front of the shop window. This is usually a narrow beam spotlight for highlighting special details or for making dramatic lighting effects from below. In practice, this is not usually done.

US2011/0310598a1 discloses a lighting assembly and method for substantially uniformly illuminating a vertical planar area by a plurality of LEDs.

Disclosure of Invention

It is an object of the present invention to overcome at least one of the above mentioned drawbacks of the known lighting device or the known lighting system.

To this end, the invention discloses an illumination system comprising at least a first and at least a second illumination device, each illumination device comprising a first plurality of illumination units mounted in a first direction along the length of an elongated carrier, each illumination unit being mounted in a respective fixed predetermined orientation, the illumination device being configured to directly project a plurality of light spots,

wherein the first plurality of spots extend only in a second direction transverse to the first direction,

wherein the at least first and at least second lighting devices are substantially in line in a length direction,

wherein the first lighting device has a first light source configured to emit first light having a first color, color temperature or CCT, and the second lighting device has a second light source configured to emit second light having a second color, color temperature or CCT different from the first light, and

wherein the first light source is configured to provide light of a first intensity and the second light source is configured to provide light of a second intensity lower than the first intensity.

In short, a row of first lighting units and a row of first light spots projected thereby extend only in mutually transverse directions. In this connection, the expression "lateral direction" means a second direction which makes an angle Δ with the first direction, for example 75 ° < = Δ < = 105 °, preferably 85 ° < = Δ < = 95 °, such as Δ = 90 °. For example, a first plurality of spots may be projected on a facing target plane P extending generally in said first direction and a second direction transverse to said first direction, wherein the illumination device is offset from the setting plane P in a different third direction.

For those skilled in the art, the first light source is configured to function as a main lamp and the second light source is configured to function as a fill lamp. Typically, the first lighting units are arranged consecutively, and when all first lighting units are in the on-mode, the light spots in the row of first light spots are also arranged consecutively.

Typically, the lighting device comprises a plurality of lighting units mounted on the elongated carrier in a first direction, each lighting unit being mounted in a respective fixed predetermined orientation, the lighting device being configured to project a plurality of light spots directly onto a facing target plane P (extending generally in the first direction and a second direction transverse to the first direction), wherein the plurality of light spots extend at least in a second direction different from the first direction, and wherein the lighting device is offset from the plane P in a third direction different from the first and second directions.

The lighting device may have the following features: the first, second and third directions are the X, Y and Z directions, respectively, of a cartesian coordinate system. The lighting device then has the following features: it comprises a plurality (e.g. a row of units) of lighting units mounted on an elongated carrier in a first direction, each lighting unit being mounted in a respective fixed unique predetermined orientation and being configured to generate a unique light beam having a beam angle and a fixed unique orientation to generate a unique light spot on a target plane P, the lighting device being configured to project a plurality (e.g. a row of spots) of said light spot directly on the target plane P, said plane P extending in said first direction X and a second direction Y transverse to said first direction, wherein said plurality of light spots extends in the second direction, and wherein said lighting device is offset from said plane P in a third direction Z. The lighting device may be in a tilted position with respect to the (virtual) plane P. Furthermore, the lighting device may have at least one of the following features: the respective fixed predetermined orientation is unique for each lighting unit and each lighting unit has a respective fixed beam angle. Since most shop windows can be seen as 3D rectangular boxes, the first, second and third directions can most easily be defined by orthogonal XYZ coordinate systems, simplifying the computer modeling, computer manipulation/control of the shop window lighting pattern. Thus, the lighting device may have the following features: the row of pre-oriented lighting units is linear and extends in either the X, Y or Z direction to easily fit into the orthogonal XYZ rectangular coordinate system.

In the context of the present invention, the following should be understood:

substantially each lighting unit comprises a light source, preferably > ═ 1 LED, and a respective associated optic. Alternatively, the plurality of lighting units may generate different beam angles and color temperatures to enhance the lighting scene by the so-called mccandelas (mccandles) method, which is also used in dramatic stage lighting;

a fixed, uniquely oriented, predetermined means that there are no optical axis pairs of lighting units extending in parallel;

directly means without the use of (remote) additional optics, such as mirrors, reflector lenses, deflectors;

the rows need not be linear but may be curved.

The disclosed lighting device according to the invention as claimed in the independent claim and further claimed in the dependent claims alleviates at least one of the above disadvantages but in practice most or all of them.

A first important feature of the lighting device of the invention is the miniaturization of the hardware, i.e. the miniaturization of the device for illuminating the shop window. Subsequently, substantially all lighting units of the lighting device have LEDs as light sources embedded in a thin carrier (e.g. a strip) with a cross-sectional diameter of a few centimeters at most, typically 3 to 5 cm, and a length of typically between 15 cm and 180 cm, a length of typically 60 cm per unit length or a multiple thereof, as these are typically the unit lengths used for ceiling tiles of false ceilings. This miniaturization is achieved by: (1) the method comprises the steps of (1) decomposing a small number of large spotlights from the prior art into line-or matrix-lighting devices with a large number of lighting units to generate a large number of beamlets, and (2) orienting each lighting device such that the projected beamlets of the lighting units (which require relatively small lighting units, and therefore small beam-forming optics) follow a line rather than a broad matrix.

The lighting device may have the following features: it comprises at least one further plurality of lighting units extending only in said first direction, said at least one further plurality of lighting units being configured to directly project further light spots so as to form a combined overall light pattern together with the first plurality of light spots projected by the first plurality of lighting units. The lighting device may have the following features: a plurality of additional spots are projected parallel to and adjacent to the first plurality of spots. The lighting device may have the following features: at least one additional plurality of lighting units is located in the extension of the first plurality of lighting units. The lighting device may have the following features: the second or the second and third plurality of lighting units of the at least one further plurality of lighting units are arranged in parallel and in close proximity to the first plurality of lighting units.

It is possible that the lighting units are not placed on a single line, but that the first lighting unit and the second lighting unit are placed in an XY matrix, but wherein the number of lighting units in the X-direction (or first direction) is much larger than the number of rows positioned parallel to each other in the Y-direction (or second direction). In general, when referring to a lighting unit, this may comprise the first, second and/or further lighting units, wherever applicable. Similar statements apply to one or more of the spots, i.e. to the spots comprising the first, second and/or further rows. Typically, the number of parallel extending rows (in the Y-direction) of the first and second lighting units is 1 to 3, such that the width of the lighting device is in the range of about 2 cm to 8 cm, while the number of lighting units per lighting device in the first direction (or X-direction) is at least 5 or 7, or typically about 20 to 60 lighting units per lighting device, such that the length of the lighting device is in the range of about 15 cm to 200 cm. This results in an aspect ratio Rld of the lighting device, i.e. the length divided by the width, in the range 3 ≦ Rld ≦ 100.

The advantage of the conversion of a plurality of illumination units extending in the X-direction and a plurality of light spots thus projected extending in the Y-direction transverse to the X-direction is: it is possible to have a larger number of illumination spots extending in the Y-direction than the number of parallel extending rows arranged in the Y-direction and/or to improve the distribution of the (local) thermal load of the lighting device or system. Consider the case of a uniformly illuminated vertical surface by a plurality of parallel rows of lighting devices positioned offset in the Z-direction, vertically above the vertical surface. If each row of lighting devices projects a corresponding row of light spots extending in the same direction, the row of lighting units arranged closest to the corresponding portion of the vertical surface being illuminated operates at a relatively dark level, while the row of lighting units arranged furthest from the corresponding portion of the vertical surface being illuminated operates at a relatively enhanced level. This results in an unbalanced, local, disadvantageous, high thermal load of the lighting device or system, whereas in the lighting device or system of the present invention the thermal load is evenly distributed since the closest and farthest parts of the illuminated surface are illuminated by the same lighting units of the same lighting device.

Preferably, the beam is generally aimed at about 45 degrees from the horizontal X-direction and 45 to 60 degrees from the vertical axis Y-direction for the desired accent illumination of objects in the shop window. However, due to the limited space in the shop window, all positions of the target area may not be reached from such an angle. For example, if all beams are aimed 45 degrees to the right, the left corner of the target area of the shop window will be darkened. Therefore, preferably, the beam direction varies with the position of the lighting unit (or spotlight). The light beams emitted from the lighting devices are thus aimed in such a way that the entire vertical plane in the shop window is more or less uniformly illuminated by a rectangular matrix of light spots, called pixels or light spots (for main-fill light spots). The first and second groups of lighting units are individually positioned and oriented in such a way as to provide spots to a specific area as a whole. The arrangement may be a square matrix, but a hexagonal spotlight layout or any other tiling of light spots is also possible. But at least the spots comprise a first row of spots, being a subset of spots, which first row of spots extends transversely to the direction of the first lighting unit projecting the row of spots. Preferably, the spots comprise at least one second (or further) row of spots substantially parallel to the first row, and thus the stitching light pattern may form a continuous/closed illumination pattern on the target area in a generally (vertical) plane, e.g. when the target area is positioned at an average distance of at least 1 meter from the illumination device. Typically, for shop window lighting, the distance between the lighting device and the target area is in the range of 2 m to 4 m.

Simulations have been performed on embodiments according to the present invention, providing satisfactory results. In the simulation, a 3 m wide shop window was illuminated by an illumination strip having 140 beamlets covering an area 2.1 m high and 3 m wide. The spot spots are spaced 30 cm vertically (7 spots per column) and 15 cm horizontally (20 spots per row). Each beam is created by a high power LED with a 200-400 lm output in combination with beam forming optics (e.g., a 10 mm diameter TIR lens) to create a beam with a narrow spot having a width of about 10-12 degrees FWHM and a wide beam spot of typically 30-40 degrees. The aiming direction in the vertical plane is determined by the light points illuminating the head and chest of the manikin: preferably, the vertical angle is in the range of 45 to 60 degrees. The higher and lower rows of spots may deviate from this rule. The beam angle in the horizontal plane varies linearly between 0 degrees for the left column of spot spots to 45 degrees for the right column of spot spots. Of course, the variation may also be concentrated in the left part of the strip (e.g. the first meter), so that the angle of the right part of the strip may be constant at 45 degrees. In a modular approach, the bar may be made up of a left side segment with a linearly varying angle and any number of segments with a constant angle to accommodate shop windows of different widths. In this way, the potential problem of a dark corner of a shop window is solved, for example in case all main lights are at a horizontal angle of 45 degrees. If the window is wide, this is only a transition area and the largest part of the shop window can be illuminated with all main lights at an angle of 45 degrees. Thus, in a modular approach, the corner pieces have varying horizontal angles, while the rule pieces have fixed angles.

Since the lighting device is small in two dimensions and long in only one dimension, the visual (blocking, disturbing) impact on the viewer is very limited. Thus, a lighting system can be formed along the shop window, which is unobtrusive even if it is placed at an optimal height for illuminating objects, e.g. 2 m to 2.5 m above the floor, when a plurality of lighting devices are combined substantially in a line in the horizontal length direction (vertical direction is the direction of gravity) along the horizontal length of the shop window. This is advantageous compared to conventional solutions, where a bulky spotlight has to be positioned on the ceiling (typically 3.5 m above the floor) to avoid visible disturbing effects of the spotlight.

For ease of understanding the present invention, it is illustrated only by the following examples. For shop window lighting, the vertical height of the target area to be illuminated is typically in the range of 1 m to 3 m, which means that if each lighting device, which is about 30 cm in length and comprises about 10 lighting units, is to illuminate up to about 3 m of the full vertical height by main lighting (the number of lighting units may be different, i.e. smaller, for example half or a quarter of the number of main lighting units for fill lighting), then the distance between the lighting units at both ends of the lighting device, which is about 30 cm, should be enlarged to give projected spots about 3 m apart, and each lighting unit preferably gives projected spots about 30 cm in diameter to provide the desired continuous/closed lighting pattern on the target area. This may be achieved by a lighting device wherein each lighting unit is mounted in a respective fixed unique predetermined orientation. To facilitate the manipulation of the illumination units, it is convenient that the illumination device is a relatively small entity comprising a limited number of illumination units and is adapted to generate only a single column of light spots on the target area. Using individual illumination devices in a line, a plurality of columns of spots in close proximity to each other can be generated on the target area. Thus, in an illumination system comprising n illumination devices in a line, a target area with a vertical height of 3 m times a horizontal width of n x 30 cm may be completely and continuously illuminated (and thus without unlit dark holes or optical gaps) by the illumination system (this is generally applicable to main illumination, for which the spot size may be different, i.e. larger, e.g. about 60 to 100 cm in diameter). By switching on/off the desired lighting units of the lighting device/lighting system, a desired light pattern over the entire (2D) target area is obtained. However, such a 2D pattern may also be obtained by a single large lighting device. Although the diameter of the spot and the pitch of the spot are correlated, they do not necessarily have to be the same. If the diameter is much larger than the pitch, the overlap of adjacent spots will be much larger. The diameter may not be too small as this may cause gaps (dark portions) in the illumination pattern on the target area.

The application of the lighting device and lighting system of the invention is not limited to shop window lighting but is also applicable to other applications such as in-store display areas, level surfaces, street lighting, facade lighting, museum lighting, wall washing, etc.

Alternative ways of describing more or less the same or similar inventions are:

-a lighting device comprising a row of lighting units mounted in a first direction on an elongated carrier, each lighting unit being mounted in a respective fixed unique predetermined orientation, said row of lighting units of the lighting device being configured to directly project (on a target plane P) a row of light spots extending in a second direction Y substantially transverse/angled to the first direction, wherein no single plane can be identified in which both the row of lighting units and the row of light spots extend.

-a lighting device comprising a row of lighting units mounted in a first direction on an elongated carrier, each lighting unit being mounted in a respective fixed unique predetermined orientation of the respective optical axis, wherein the lighting device is configured to emit a row of light beams of said respective row of lighting units, which row of light beams realized by said fixed unique predetermined orientation is rotated spirally as a whole and projected directly into a row of light spots extending in a second direction (in plane P) transverse or angled to the first direction.

-a lighting device comprising a row of lighting units immovably mounted and extending in a first direction on an elongated carrier, each lighting unit being designed to emit a respective light beam along a predetermined optical axis of a respective fixed unique orientation, said row of lighting units of the lighting device being configured to emit a row of said light beams, which row of light beams realized by said fixed unique predetermined orientation together is spirally rotated and directly projected as a row of light spots extending in a second direction on a plane P inclined with respect to the first direction.

-a lighting device comprising a plurality of lighting units mounted in a first direction on an elongated carrier, each lighting unit being mounted in a respective fixed predetermined orientation, the lighting device being configured to directly project a plurality of light spots (on a facing target plane P), wherein the plurality of light spots extend at least in a second direction different from the first direction (and wherein the lighting device is offset from the plane P in a third direction different from the first and second directions).

In the context of the present invention, helical rotation is meant to include both torsion axes, where the translation axis and the rotation axis coincide, and situations where the translation axis and the rotation axis do not coincide, and tilting is meant to be at an angle of at least 45 degrees.

The lighting device may have the following features: the individual solid beam angles of the individual light units are such that all light spots have substantially the same shape. Preferably, the size of all the spots is also substantially the same. Thus, the design of the desired illumination pattern is simplified. The lighting device may have the following features: the stereo beam angle is related to the angle alpha between the respective optical axis and the normal of the (plane of the) tilted target area. In general, the following relationship applies to generating a circular spot on an inclined plane:

tanß1= D *cosα/（2 * L + D *sinα）

tanß2= D *cosα/（2 * L-D *sinα），

wherein beta 1 and beta 2 relate to the angle of the beam width of the part of the inclined surface of the target area further away from the lighting unit and the half-beam parts of the part of the inclined surface closer to the lighting unit, respectively on both sides of the optical axis of the lighting unit, respectively.

Thus, the spot or spot size of the plurality of illumination units to be projected on the target area appears to be substantially the same circular shape and/or size as each other.

The lighting device may have the following features: the carrier is rigid, i.e. the carrier does not substantially deform under its own weight. Thus, the mounting of the illumination device is simplified, and/or the aiming of the beam at the target area is relatively easy, since no separate mounting construction/carrier is required.

The lighting device may have the following features: the fixed orientation of the illumination unit is such that a single quadrant is substantially illuminated when viewed in projection in the first direction. The first lighting unit has a respective first optical axis and further lighting units of the plurality of lighting units have respective further optical axes, wherein a minimum angle Θ between the optical axes of the lighting units in a projection view along the first direction is in the range of 0 ° to 90 °, for example 10 ° to 80 ° or 25 ° to 70 °, such as 55 °. Note that the two intersecting axes enclose a minimum and a maximum angle, here the minimum angle. Typically, the lighting device/lighting system is positioned slightly vertically offset (defined with respect to the direction of gravity) with respect to the target area and about 1 m in front of the target area, i.e. about 1 m in front in the Z-direction, and then the optical axes of the light beams emitted by the lighting device and aimed at the target area, which need to cover the entire vertical height of said target area, are typically at a mutual angle in said range of 10 ° to 80 °.

The lighting device may have the following features: the sequence of first lighting units has a different sequence of light spots, e.g. a spread or crossed configuration, in the first plurality of light spots in the tiled lighting pattern. In this context, different sequences means that adjacent spots (to be) projected, generated by a sequence of adjacent lighting units in the lighting device, have no detectable same sequence. The row position of the illumination unit does not necessarily correspond to the row position of the spot pixels/spots and can be chosen arbitrarily. Thus, for example, the lighting unit positions in the strip may be optimized to distribute the thermal load, e.g. not located adjacent to each other, but still in the projected 2D pattern, the generated spots do lie adjacent to each other to form a closed pattern. Alternatively, the lighting device according to any one of the preceding claims, wherein the sequence of lighting units has the same sequence of light spots in the tiled lighting pattern, which makes the lighting device intuitively easy to control. In this context, the same sequence means that there is a detectably same order of adjacent spots (to be) projected, generated by adjacent lighting units having an order in the lighting device.

The lighting device may have the following features: the illumination unit is configured to generate a light beam having an adjustable stereoscopic beam angle. The manner of such adjustment is well known in the art. Thus, the size of the spot/spot projected on the target area can be adjusted if needed and/or desired. Typically, the spot size has a diameter D, which can be varied by changing the stereoscopic beam angle and the distance between the illumination unit and the target area. The spot size D is related to the beam angle beta and the distance L between the light source/illumination unit and the target area according to the following formula:

D = 2 * L *tanß

thus, the variation of the spot angle beta in the vertical direction with distance L is as follows: tan β = D/2L.

Therefore, the spot sizes of the plurality of illumination units to be projected on the target area are made to be substantially the same size as each other.

The lighting device may have the following features: the beams generated by the illumination units each have an ellipse shape, the ellipses of the ellipse shape having a large radius and a small radius, wherein the large radius of each ellipse extends in a direction orthogonal to the direction of incidence on the target area such that the spot or spot size formed by the beams on the target area is substantially circular. If the direction of incidence is not parallel to the normal to the target area, the diagonal of the spot on the target plane becomes an enlarged diagonal in the plane spanned by the normal to the target area and the direction of the incident beam. Thus, in the beam emitted from the illumination device, the spot diagonal perpendicular to this enlarged diagonal should be increased so that when the beam hits the target area, a substantially circular spot is obtained (explained in more detail with reference to fig. 8A-B).

The lighting device may have the following features: each spot in a row of spots on the target area has substantially the same (peak) illumination level. In this context, substantially the same means that the ratio between the highest and lowest illumination levels is between 0.5-2. In general, the difference in the illuminance level by a factor of two is not observable by the human eye and is therefore considered to be uniform in the illuminance level. The same illumination level can be easily obtained by measuring the illumination level in the target area and then adjusting the power and thus the light output of the individual lighting units individually.

The first rough mathematical relationship to obtain the first preliminary settings for the individual lighting units is based on:

I → (2*L*tanα)²(or differently denoted: I → D)²)

Where α is the angle between the respective optical axis and the (plane of the) tilted target area, where α is typically in the range of 5 ° to 85 °, and where L is the distance between the respective lighting unit and the target area. Thus, it is obtained that approximately the same beam intensity (lux) is obtained at each position of the target area, resulting in a relatively high uniformity of the illumination level in the target area. Optionally, the beam intensity of each illumination device is independently controllable and adjustable to further optimize the desired illumination pattern on the target area.

The lighting device may have the following features: the plurality of lighting units comprises ten to three thousand lighting units per meter, preferably between twenty-five and three hundred, more preferably between thirty and fifty. By increasing the number of light units, which requires at least three or five, but preferably at least ten (e.g. suitable for street lighting), more complex desired light patterns of spots on the target area with higher resolution can be obtained. However, too many lighting units involve the risk that the control/manipulation of the lighting device becomes too complex, thus limiting the upper limit to preferably at most one thousand. A convenient number of lighting units is between twenty-five and three hundred and ranges from thirty to sixty in order to maintain compactness and still good resolution.

The lighting device may have the following features: the aspect ratio AR of the light pattern covered by the array of light spots is within a range of 3 to 50. Typically, for shop window lighting, the vertical height and width of the target area to be illuminated by a single lighting device is 2 to 3 m by about 0.2 to 0.4 m, which corresponds to an aspect ratio AR in the range of 5 to 15.

The lighting device may have the following features: substantially each lighting unit comprises at least one respective associated LED, and the at least one associated LED comprises LEDs of different colors, color temperature and/or CCT. Thus, the versatility of the lighting device to provide a desired lighting pattern is increased. For each lighting unit, the bundle, color temperature and/or Correlated Color Temperature (CCT), etc. of the lighting unit may be fixed or adjustable. Especially when adjustable, the at least one light source of the lighting unit comprises more than one LED, and each light source is individually controllable.

The invention also relates to a lighting system comprising at least a first and at least one or further lighting device according to the invention and which are substantially mutually in line in the length direction, preferably the number Nld of further lighting devices being 1 < = Nld < = 100, more preferably 2 < = Nld < = 60, even more preferably 5 < = Nld < = 25. In this connection, in a line means that the lighting devices extend parallel to each other and/or as a continuous row of lighting devices. The horizontal width of the shop window is wide, i.e. the width may range from less than 1 m to over 10 meters (while the height of the shop window is typically only in the range of about 2 m to 4 m). Depending on the horizontal size of the shop window and also on the degree of overlap of the spots/spots (e.g. when main and complementary light is required for a specific position of the target area), the number of lighting devices may range from only 2 to hundreds, e.g. to provide the target area completely with the required lighting pattern. Therewith, the lighting system may have the following features: the fill-in light patterns of the first and the at least one further lighting device match each other/form a closed pattern, i.e. a pattern without unlit/dark spots/light holes.

The lighting system may have the following features: it comprises at least two parallel lighting devices extending adjacent to each other in a first direction. The lighting system may further have the following features: the light sources from the first lighting device and the at least one second (or further) lighting device are positioned in a staggered configuration, in this connection "staggered configuration" means "arranged in an alternating zigzag configuration along the length direction" and/or having a tunable overlap/can be mutually offset in the first (or length) direction. The number of parallel extending strips should be kept relatively low, for example at most three, so that the cross-sectional dimension of the illumination system is relatively small and thus remains relatively inconspicuous. Alternatively, the lighting system may have the following features: two rows of light sources are included on a single luminaire, with the light sources from the first and second luminaires positioned in a staggered configuration and/or with adjustable overlap/being mutually movable in the length direction. Thus, multiple spots generated by either alternative may be targetedThe main light and the supplementary light are provided at the same part of the target area, and thus, for example, at said same part. Alternatively or additionally, it is also possible that: the first lighting device has a first light source of a first color, color temperature or CCT, and the second lighting device has a second light source of a second color, color temperature (Tc) or CCT different from the first light source. Further alternatively or additionally, the lighting system may have the following features: the first light source functions as a main lamp and is configured to provide light of a first intensity, and the second light source functions as a fill-in lamp and is configured to provide light of a second intensity lower than the first intensity. All these features together constitute the versatility and possible field of application of the illumination system of the invention. In this regard, expressions like lower intensity and higher intensity may, but do not necessarily, mean that the total luminous flux emitted by the second light source is lower or higher than the total luminous flux emitted by the first light source, but are intended to mean that the luminous intensity in candela (i.e. lumens/sr) is lower or higher, and/or in lux (i.e. lumens/m)²) The indicated illumination level of the target area is lower or higher.

The beam widths of both the main lamp and the fill lamp may be the same, but it is considered that the fill lamp should have a lower illumination level on the target area than the main lamp. Furthermore, the lighting system with the adjustable lighting device enables the lighting system to be switched between the light sources, i.e. when the main light and the fill light use the same beam width, the main light from the right side and the fill light from the left side can be easily switched over to each other. The switching can then be easily done, for example, for color, Tc, CCT, and illumination level or flux.

The lighting system may have the following features: the first light source is configured to increase the intensity of the first light as the intensity of the ambient light increases and decrease the intensity of the first light as the intensity of the ambient light decreases, and the second light source is configured to decrease the intensity of the second light as the intensity of the ambient light increases and increase the intensity of the second light as the intensity of the ambient light decreases. In other words, the intensity of the main light and the intensity of the fill light depend on the level of the ambient light inversely to each other. This enables the lighting system to adjust the scene settings to be displayed to suit the actual environmental conditions. In particular, when the ambient light level is relatively high, the primary light is enhanced to a level above the ambient light level to maintain its eye-catching highlighting function and/or to place emphasis on desired features in the scene. On the other hand, since much fill light is already provided via the ambient light, the intensity of the fill light provided by the lighting system may be dimmed. Vice versa, when the ambient light level is relatively low, the intensity of the primary light will be dimmed, but still remain above the ambient light level, since a lower intensity of the primary light is required to maintain its prominent function. On the other hand, since there is little fill light provided by ambient light, the intensity of fill light provided by the lighting system is increased, but still below the intensity of the main light, to maintain the main light's prominent function.

The lighting system may have the following features: the number of light sources on each luminaire is equal to N and is preferably configured to generate a 2D pattern with N light spots. In case N is equal on each lighting device, each target portion of the target area may be individually controlled by at least two light beams, e.g. providing each target portion with at least two different colors and/or primary and supplementary light. Thus, a single spot in a row of spots comprises both the first light (or main light) and the second light (or fill light). It is noted that the features of a single spot comprising both main light and fill light can be obtained both by a single lighting device (and the lighting system then comprises at least two of these lighting devices), and by a plurality of lighting devices.

The lighting system may have the following features: the number of the first light sources or the main lamps is two to twenty times of the number of the second light sources or the supplementary lighting lamps. Thus, a simpler but still relatively complex illumination system is provided. The lighting system may have the following features: the first light source is configured to provide a light beam of a first width typically in a first range of 5 to 30 degrees and the second light source is configured to provide a light beam of a second width wider than the first width, typically in a second range of 30 to 70 degrees, such that one second light source cooperates with the plurality of first light sources.

The lighting system may have the following features: the first light source is configured to project first light in a first direction, e.g. as a first light beam, and the second light source is configured to project second light in a second direction, e.g. as a second light beam, at an angle γ to the first direction, γ being in the range of 10 ° to 160 °, typically in the range of 40 ° to 120 °. Typically, the first light source and the second light source are positioned relative to each other in such a way that the first light beam and the second light beam cross each other, such that the first light beam and the second light beam are incident on the same specific point of the light region from different directions, e.g. from directions on both sides of the same specific point, such as from opposite directions. Thus, a so-called macanderis effect can be obtained, which is known to particularly enhance the attractiveness of displayed items illuminated in this manner. Note that the macranthes effect can be obtained by a single lighting device (and the lighting system includes at least two of these lighting devices), or by a plurality of lighting devices.

The lighting system may have the following features: it further comprises a third light source substantially in line with the light sources mounted on the first and further carriers. It may then have the following features: the third light source is configured to provide light having a third intensity higher than the first intensity of the first light, preferably higher than the combined intensity of the first and second light, for example to function as a beamlet lamp. Alternatively, the lighting system has the following features: the third light source is arranged on a separate substrate not in line with the light sources mounted on the first and further carriers. It may then have the following features: the third light is not arranged in a line and is configured to emit light substantially in a direction opposite to the emission direction of the first light source, the third intensity being lower than the first intensity. Typically, then the third light source is adapted to act as a backlight to further enrich the desired scene, but in combination with the backlight a subset of the third light sources may be configured to provide upstream light. The backlight and the upstream light may propagate in substantially the same direction, and then the third light source may be comprised in a single lighting device providing both said backlight and upstream light.

It is further desirable that the lighting system has the following features: the third light source is configured to emit third light of a third color different from the first color of the first light. The illumination system may provide both beamlet light and backlight, and in turn the illumination system comprises a combination of the illumination device and a third light source, a subset of which is configured to provide beamlet light and another subset is configured to provide backlight. Thus, the third light may be an uplight or a beamlet light. In order to cooperate with a backlight, a thin beam or an upward-illuminating spotlight is also used. This is a spotlight which is usually mounted at the bottom in front of the shop window. This is usually a narrow beam spotlight for highlighting special details or for making dramatic lighting effects from below. To further enhance the lighting effect, flickering of the main and/or beamlet light may be included in the scene setting.

The lighting system may have the following features: comprising at least one first illumination device comprising a plurality of illumination units mounted on an elongated carrier in a first direction, each illumination unit being mounted in a respective fixed predetermined orientation, said illumination device being configured to project a plurality of light spots directly on a facing target plane P,

wherein the plurality of light spots extend at least in a second direction different from the first direction, and wherein the lighting device is offset from the plane P in a third direction different from the first and second directions, an

Wherein the lighting system further comprises a control unit for individually controlling/addressing the lighting units of at least the first and the further lighting device. This feature enables to manage the local thermal load of the lighting devices of the lighting system and helps to reduce the maximum temperature of the (local) thermal load of the system. It is also convenient if all lighting units of the respective lighting device can be switched on/off simultaneously by a single switch, since cumbersome actions can be reduced if one wants to (de-) activate the whole lighting device. The same applies if the lighting system comprises at least two parallel rows of lighting devices, for example two, three, four or five parallel rows, for switching on/off the entire row of lighting devices. Furthermore, the lighting system with an adjustable lighting device enables the lighting system to be electronically switched between the light sources by using the control unit, i.e. the main light from the right side and the fill light from the left side can be easily switched to each other when the main light and the fill light use the same beam width. The switching can then be easily done, for example, for color, Tc, CCT, and illumination level or flux.

The lighting system may have the following features: the illumination system further comprises at least one second illumination device comprising a plurality of illumination units mounted on the elongated carrier in respective first directions, each illumination unit being mounted in a respective fixed predetermined orientation, said illumination device being configured to project a plurality of light spots directly on a facing target plane P,

wherein the plurality of spots extend at least in respective second directions different from the first direction,

wherein the lighting devices are offset from the plane P in a third direction different from the first and second directions, the at least first and at least second lighting devices being substantially in line in the length direction.

The lighting system may have the following features: the control unit includes a graphical display configured to display the patched pattern. The patch pattern is typically formed by a line of spots on the target area. Optionally, the lighting system may have the following features: the control unit comprises a camera configured to monitor, photograph and/or display said patched pattern in situ and/or in real time. This is a straightforward way to see the effect of turning on/off the respective lighting units, thereby simplifying the setting of the (desired) light pattern. The camera may be or comprise a sensor as an integrated (built-in) and/or non-integrated (stand-alone) device to measure actual (ambient) lighting conditions to instantly adjust the light intensity of the beam projected on the target area, e.g. such that when the ambient light level is low, such as evening or night, the light level provided to the shop window is reduced to counteract glare and/or excessive lighting, or during periods when bright sunlight is present, the lighting provided to the shop window is enhanced to still attract (potential) customers' attention to the items displayed in the shop window.

The lighting system may have the following features: the control unit is configured to be programmable by the scene to provide a dynamic lighting scene on the target area. Thus, an improved presentation and/or an increased attention to (potential) customers for the items displayed in the shop window is obtained. In order to enable the lighting system to automatically adjust the scene settings to suit the actual environmental conditions, the lighting system may have the following features: the type of programmable scene displayed/executed depends on the time of day and/or ambient light level.

The lighting system may have the following features: the graphical display comprises a touch screen by means of which the lighting unit can be controlled. This provides a user-friendly interface for the lighting system.

The lighting system may have features configured as shop window lighting. However, applications in street lighting or indoor lighting are also envisaged, for example in theaters, bars and/or hotel lobbies.

The invention also relates to a lighting method using a lighting system according to the invention, said method comprising the steps of:

-selecting a scene for the target area;

-selectively turning on the lighting units to create a patched lighting pattern;

-evaluating the lighting effect obtained on the identified scene/target area.

The lighting method may further include the steps of:

-adjusting the obtained lighting effect.

Typically, the setting of the scene settings, such as for shop windows, may be done locally, i.e. at the location of the shop window itself, but alternatively or additionally the scene settings may be done remotely, e.g. by an expert from a central location where the individual shop windows of the various branches of the shop chain are controlled by the expert. Thereupon, the method may be performed from a remote location and comprises the steps of:

-taking a shop window in which a scene is to be set;

-transmitting the image to a remote control station via electronic means;

-performing the steps of the claims, selecting a scene for the target area;

-evaluating the lighting effect obtained on the identified scene/target area, and

optionally comprising the steps of:

-adjusting the obtained lighting effect via remote control at the remote control station.

Generally, images (photographs) are in digitized form, and electronic means of transferring images are well known, such as via the internet, e-mail, wireless data communication systems. Instead of executing the method step by step from a remote location, instructions for a new scene setting may also be collected and sent as a set of instructions to the target shop window. The method also enables monitoring and/or maintaining the status of a specific shop window, upon detecting a failure of an active device of the lighting system, a signal for repairing the system may be created, but alternatively or additionally, settings of other devices of the lighting system may be adjusted from a central, remote location to compensate for the failure of the active device.

Drawings

The invention will now be further elucidated by means of schematic diagrams describing various embodiments, which are not intended to limit the invention, but rather to illustrate the generality of the invention. In the drawings:

FIG. 1A shows a perspective view of a shop window for explaining the principles of the present invention;

FIG. 1B shows a detail of the three lighting units of FIG. 1A;

1C-D show front and side views of a shop window to further explain the principles of the present invention;

2A-B show front views of a shop window, wherein a target portion of a target area is illuminated by two respective lighting units;

3A-D show various arrangements of lighting devices and lighting units in a lighting system according to the invention;

FIG. 4 illustrates that the resolution of primary light over a portion of a target area obtained by the illumination system illustrated in FIGS. 3A-D is higher than the resolution of fill-in light;

5A-B illustrate some examples of interleaving;

fig. 6 shows a lighting system comprising parallel extending lighting devices with adjustable overlap;

fig. 7 shows a comparison between conventional shop window lighting and shop window lighting using a lighting system according to the invention;

8A-B illustrate the mathematical relationship between the position of the illumination unit relative to the target area, the beam shape and the shape of the projected spot on the target area;

fig. 9 shows a control unit for individually controlling/addressing lighting units of at least a first and a further lighting device; and

fig. 10 shows a sequence of steps to be followed to set the desired scene.

Detailed Description

Fig. 1A shows a perspective view of a shop window 1000 provided with displayed items 1002 for explaining the principles of the present invention. It shows a first lighting device 1 comprising a linear row of eight lighting units 3, the eight lighting units 3 being mounted and extending on an elongated carrier 5 only in a first direction X. Alternatively, the lighting device, the carrier and/or the row of lighting devices may have a slightly curved shape, for example over an angle of curvature of at most 30 °. Each lighting unit 3 is mounted in a respective fixed, unique predetermined orientation, as indicated by the respective optical axis 7. The first lighting device 1 is configured to project a first row of spots 9 directly on the target area 11 (i.e. on a plane P in which the displayed items 1002 are located), the plane P extending in the first direction X and in a second direction Y transverse to the first direction, i.e. Δ ≈ 90 °, but possibly slightly deviating (Δ = 90 ° when the XYZ directions are according to an orthogonal cartesian coordinate system). The first row of spots 9 extends only in the second direction Y and forms a closed pattern 13. The lighting device 1 is displaced from the plane P in a third direction Z. The sequence of the illumination units 3 is different from the sequence of the spots 9 in the patched illumination pattern 13, but is arbitrarily chosen to reduce or optimize the local thermal load. In the shading (indicated by the dashed line drawing) a further or next lighting device 1 'is indicated, which lighting device 1' comprises a next row of lighting units 3 'and their corresponding next row of light spots 9'. As shown, the next (or another) lighting device 1' is substantially in line with the first lighting device 3 in the length direction X and forms together with the first lighting device 3a lighting system 100. It is also shown that the next row of spots 9 'is projected on the target area 11 adjacent to the first row of spots 9, which together match and form a closed pattern 13'.

Alternatively, fig. 1A may be considered to show only a single lighting device. The first and further lighting devices shown in fig. 1A are integrated into one lighting device, the lighting unit 3 of the first lighting device being a first plurality of lighting units 3 projecting a first plurality of light spots, and the lighting unit 3' of the further lighting device 1' being referred to as a further plurality of lighting units 3' projecting a further plurality of light spots.

Fig. 1B shows a detail of three (first) lighting units 3 of the lighting device 1 of fig. 1A. For each lighting unit 3, a respective light source (in the figure a respective LED), a fixed respective reflector with a fixed respective optical axis 7 is shown. Also shown is a normal 14 (orthogonal line) to a main surface 15 of the elongated carrier 5 of the lighting device 1, the carrier 5 having a length Ld. As shown, each respective optical axis is at a respective angle to the normal. Furthermore, the first lighting unit 3a has a respective first optical axis 7a and at least one

further lighting unit

3b, 3c in said row of lighting units has a respective further optical axis 7b, 7c, wherein the maximum angle Θ between said optical axes 7a-7c is in the range of 10 ° to 80 °, in the figure Θ being about 60 degrees.

Fig. 1C-D show front views of a shop window 1000 for further explaining the principles of the present invention. Fig. 1C shows a lighting system 100 comprising a first row of six (first and further) lighting devices 1 located at a height of about 2.2 m above an item 1002 displayed in a shop window. For the sake of simplicity, each lighting device 1 comprises only four lighting units 3. The first lighting device 1a is configured to generate a first vertical row (also referred to as column) of four contiguous or optionally partially overlapping spots 9a on the target area 11. In this figure, only the first illumination unit of the first illumination device is activated (switched on) and generates a first spot of primary light on the target area. Here, the sequence in the lighting units is the same as the sequence in the light spots, i.e. in the lighting device the lighting units are arranged from left to right and the corresponding light spots are arranged in the same order from top to bottom. Similar to the first illumination device, the second illumination device 1b is configured to generate a second column of four spots 9b on the target area, in this figure only the second illumination unit of the second illumination device is activated (switched on) and generates a second spot of primary light on the target area. Similarly, the third and fourth lighting devices are applied, the fifth and sixth lighting devices are inactive (counting from left to right). The illumination system thus illuminates the target area with the desired (closed) illumination pattern of the main lamp. In the figure provided by the lighting device 1g, supplementary lighting is provided in a similar manner. The spot size of the supplementary light is about three times that of the main light. In the right part of the figure, a side view of the shop window is given, showing the lighting devices for providing main light (denoted by character a), all arranged in a line, while the lighting devices for providing supplementary light (denoted by character B) are parallel to but not in a line with the lighting devices for providing main light. As shown in the right part of the figure, the mutual positions of the main light and the supplementary light are shown by the characters a and B, respectively. By activating only certain lighting units, a desired light pattern may be created to highlight desired details of the displayed item.

Fig. 1D shows a similar lighting system 100 as shown in fig. 1C, however, here the lighting system is located at the floor of the shop window 1000 for providing the upstream light as a backlight. In the illumination system of fig. 1D, all six illumination devices 1 for providing the upward light are in a fully operational state, i.e. all four illumination units 3 of each illumination device are switched on and the target area is fully illuminated by the light spots 9 of the respective vertical rows (columns), but for the sake of illustration the light spots 9, which are not shown, have an overlap, but in practice there may be or may be an overlap between adjacent light spots. Also here, the sequence in the illumination unit is the same as the sequence in the light spot. In the right part of the figure, a side view of the shop window 1000 is given, showing the position of the backlight (denoted by character C and used here as an up light) relative to the main light (denoted by character a) and the fill light (denoted by character B) in the shop window.

Fig. 2A-B show front views of the shop window 1000, wherein some target portions of the target area 11 are illuminated by the respective first lighting device 1a and the further (second) lighting device 1B. The lighting system 1 shown in fig. 2A comprises two parallel rows of

lighting devices

4a, 4b extending in a first (X) direction, wherein only some of the lighting units 3 (in the figure LED-reflector units) are switched on. The first row of luminaires 4a provides primary light to the target area 11 and the second row of luminaires 4b provides fill light to the target area of a different Correlated Color Temperature (CCT) to the primary light, i.e. a higher color temperature (Tc) or a higher CCT. The LEDs of the first lighting device emit light in a first direction on the target area and the second LEDs of the second lighting device emit light in a second direction at an angle γ to the first direction, wherein γ is in the range of 10 ° to 40 °. Therefore, a so-called macidelis effect can be obtained, and the attraction of the illuminated display articles 1002 can be enhanced.

The lighting system 100 shown in fig. 2B comprises two rows of fixed parallel lighting devices, namely a first lighting device 4a and a further lighting device 4B extending in a first (X) direction, wherein some lighting units 3 are switched on, i.e. in this case only those lighting devices are switched on, to emit both primary and supplementary light of mutually different CT or CCT to the target area where the displayed item is located. Note that the spot sizes of the main and fill spots are (approximately) equal in size. The portion of the target area to be illuminated by the lighting unit where no displayed articles are located is in the off state. Thus, it can be achieved that the display item 1002 stands out in the shop window 1000 and attracts more attention.

For example, the known lighting system may be replaced by the lighting system 100 shown in fig. 2A-B, which comprises five conventional Philips Magneos spotlights, each typically having a flux of at least 3000 lm and a size of 0.26 x 0.16 m. Typically, then, the inventive lighting system comprises as lighting unit 3 approximately 150 high power LEDs (emitting 200-400 lm each) or alternatively 300 medium power LEDs (emitting approximately 60-100 lm each). Although only a limited number of these lighting devices 1, i.e. only six lighting devices 1 per row, is shown in the schematic diagrams of fig. 2A-B, in practice the number is about eight, and each lighting device in the figures has only four LED + collimators as lighting units 3, in practice each lighting device comprises about ten lighting units. With this number of lighting units, a matrix of spots of about 8-16 pixels high and about 10-20 pixels wide can be created. The light generated by the LEDs is focused by a small optical element of each LED, typically 1-2 cm in diameter. Thus, the light bar comprises a single row of lighting devices, which may typically be about 1-2 cm wide and at least 1.5-2.0 m long. Two or three parallel rows of

lighting devices

4a, 4b together typically have a cross-section of about 6 cm diameter. It is important to note that the creation of an addressable matrix of pixels does not require excessive mounting of the LEDs: the amount of light generated will be comparable to a conventional system (installed to provide maximum light output during sunny days) and when less light is needed (evening/night), a light pattern is created by turning off the pixels.

Fig. 3A-D show various configurations of a first and a further lighting device 1 in a lighting system 100 according to the invention, each lighting device comprising three lighting units 3. By way of example, all configurations shown in fig. 3A-D have eighteen lighting units 3 of six lighting devices 1a, which provide a spot of primary light, and six lighting units 3b of two lighting devices 1b, which provide spots of supplementary light, divided into eight

lighting devices

1a, 1b in total. In the configuration of fig. 3A, the lighting system comprises two parallel rows of

lighting devices

4a, 4 b. The first row 4a comprises six lighting devices 1a in a line in the length (X) direction, and the further second row 4b comprises two lighting devices 1b in a line in the length direction and parallel to the first row. The eighteen main lamps are divided into six lighting devices of a first row 4a, each comprising three lighting units 3, and the six fill lamps are divided into two further lighting devices of a second row 4b, each comprising three lighting units. Fig. 3B-D show the same lighting device and lighting unit in an alternative arrangement, wherein in fig. 3B all lighting devices 3 are arranged in a single row 4 and in a line in the length direction (X). In fig. 3C, the same arrangement as in fig. 3A is shown, but with the additional feature: the first row of lighting units 4a and the second row of lighting units 4b are mutually displaceable along each other in the length direction (X), so that a displacement of the spot of supplementary lighting onto the spot of main light over the target area can be achieved. Fig. 3D shows an arrangement of two parallel equal-length rows of lighting devices, the first row 4a comprising twelve main lighting units 3a and the second row 4b comprising twelve lighting units, in a crossed configuration of main lighting units 3b' and fill lighting units 3b ".

Fig. 4 shows an example of a target region 11, which target region 11 is patched by a main spot 51 and a supplementary spot 53. In this embodiment, the primary spot is shown to be smaller than the fill spot, thereby achieving a higher resolution of primary light over the target area portion than fill, as obtained by the illumination system shown in fig. 3A-D. In order to completely cover the target area by both the main light and the supplementary light, the size of the light spot generated by the main lighting unit is relatively small, the size of the light spot generated by the supplementary lighting unit is relatively large, and the ratio of the size of the light spot of the supplementary light spot to the size of the main light spot is about 3. A slight overlap between adjacent spots is allowed and shown. Furthermore, each spot is numbered, their numbering corresponding to the numbering of the lighting units shown in fig. 3A-D. In most cases, i.e. except for the arrangement shown in e.g. fig. 3D, the sequence in the lighting units is the same as the sequence in the spots.

Fig. 5A-B show two examples of interleaving. On the right in fig. 5A, two examples of an illumination system 100 comprising two illumination devices 1 are shown, each illumination device 1 having an arrangement of seven illumination units 3 per illumination device, wherein the row positions of the illumination units do not necessarily correspond to the column positions of the spot pixels/spots 51 on the target area 11, as shown on the left side of fig. 5A. The numbers in the illumination units are associated with the same numbers in the target area, thus coupling the row positions of the illumination units to the column positions of the spots in the target area. The coupling of row positions to column positions may be pre-arranged according to a desired algorithm, as is the case in fig. 5A-B, but may alternatively be chosen arbitrarily. By selecting a particular arrangement, e.g. according to a desired lighting pattern, the position of the lighting units in the lighting device may e.g. be optimized to distribute the thermal load. In particular, a more uniform spreading of the thermal load can also be achieved by a layout similar to the embodiment shown in fig. 5B. In fig. 5B it is shown that in the target area 11 four light spots 51 are projected next to each other, which may result in a local thermal load in the lighting system 100 (here comprising two lighting devices 1) if the corresponding lighting units 3 generating the light spots are next to each other. However, in fig. 5B it is shown that the corresponding lighting units are more or less evenly spread over the two lighting devices 1, thereby distributing the thermal load in the lighting system. If the supplementary spots are of a wide range and overlap mostly when projected onto the target area, the exact location of the supplementary light in the illumination system is less important, which can be used to further counteract the high local thermal load of the illumination system. The fill-in light source near the hot spot (where all neighboring main lights are on) can then be dimmed and the other fill-in lights can be dimmed to compensate for this.

Fig. 6 shows a lighting system 100, which lighting system 100 comprises two rows (4 a, 4 b) of lighting devices 1 extending in parallel in the X (length) direction, the two rows having an adjustable overlap. The first row 4a comprises lighting devices 1a with lighting units 3a providing primary light of a certain Tc or CCT (e.g. 3000K), and the second row 4b comprises second lighting devices 1b with second lighting units 3b providing fill lighting of a higher Tc or CCT (e.g. 5000K). The LEDs of the first lighting unit emit light in a first direction 55 over the target area and the LEDs of the second lighting unit emit light in a second direction 57 at an angle γ to the first direction, wherein γ is about 70 °, so that a so-called macandels effect can be obtained. By mutually offsetting the second row with respect to the first row in the X-direction, the so-called macandels effect can be adjusted and/or optimized at a desired position on the target area by emitting light of mutually different CCTs with different beam angles aimed at the same position on the target area from different positions. Generally, this feature is used to specifically enhance the appeal of particular portions of the displayed item.

Fig. 7 shows a comparison between a conventional lighting system 101 for a shop window 1000 and a lighting system 100 according to the invention for illuminating the shop window 1000 in a front view and in a side view of the shop window. As shown, the conventional lighting system includes four relatively bulky, eye-catching, and relatively tall mounted conventional lighting units 102. In contrast, the lighting system of the invention has a relatively high number of lighting units, for example one hundred lighting units or more, comprised in several lighting devices 1, mounted in a relatively low position in a relatively unobtrusive manner. This gives the lighting system of the invention advantages over known lighting systems, such as:

high resolution spots illuminating the target area, providing more possibilities for creating desired more complex illumination patterns;

illuminating the same plaque on the target area using a plurality of lighting units, e.g. creating a macandels effect by using lighting units emitting light of mutually different CCTs with different beam angles aimed from different positions at the same position on the target area;

-an excellent possibility to create a dynamic lighting scene;

the installation of the desired lighting scene/pattern is easier, e.g. easier to reach or can be adjusted from a remote location (without using a ladder), and involves less risk of injury to personnel, such as shop window designers, and less risk of damaging and/or distorting the displayed items.

Fig. 8A-B illustrate the mathematical relationship between the position of the illumination unit 3 relative to the target area 11, the beam shape 59 and the shape of the projected spot 59 on the target area. The effect of distance and projection angle on the spot shape is shown in fig. 8A. In order for each respective light beam emitted by the respective lighting unit along the respective optical axis 7 to produce the same intensity I on the target area, I follows the following relation:

I → (2*L*tanα)²

where α is the angle between the respective optical axis 7 and (the plane Q of) the tilted target area 11, where α is in the range of 5 ° to 85 °, and where L is the distance between the respective lighting unit and the target area.

However, in essence, the spot becomes more or less elliptical, with a short axis that depends only on the distance between the source and the illumination plane, and a long axis that also depends on the projection angle. To create more or less circular patches with a constant diameter, the beam width must be proportional to the projection distance and the beam angle must become asymmetric (approximately elliptical) to compensate for the projection angle. The relationship between the beam angles beta 1, beta 2, the projection distance L and the inclination angle alpha is shown in fig. 8B and at least substantially follows the following relationship:

to generate a circular spot on the inclined plane of the target area 11, the respective lighting unit 3 generates a respective light beam according to the following relation:

tanß1= D *cosα/（2 * L + D *sinα）

tanß2= D *cosα/（2 * L-D *sinα），

wherein beta 1 and beta 2 relate to the angle of the beam width of the part of the inclined surface of the target area that is further away from the lighting unit and the half-beam part of the inclined surface that is closer to the lighting unit, respectively, on both sides of the optical axis 7 of the lighting unit 3, and wherein alpha is the angle between the respective optical axis and the (plane of the) inclined target area, wherein alpha is in the range of 5 ° to 85 °, and wherein L is the distance between the respective lighting unit and the target area.

Fig. 9 shows a control unit 201 for individual control/addressing of the lighting units 3 of at least a first and a further lighting device. The control unit comprises a graphical display 203, the graphical display 203 comprising a touch screen 205 as a convenient user interface and being configured to monitor, photograph and/or display in situ a patchwork pattern formed by a line of light spots on the target area. For displaying the patched pattern in situ, the control unit comprises a (real-time) camera 207. Furthermore, the control unit is configured to be programmable by the scene to provide a dynamic lighting scene on the target area. Typically, the setting of the scene settings, such as the shop window, may be done locally, i.e. at the location of the shop window itself, but alternatively or additionally the scene settings may be done remotely, e.g. by an expert from a central location where the individual shop windows of the individual branches of the shop chain are controlled by the expert. In turn, the control unit comprises a transmitting/receiving unit 209 for wireless electronic communication. When done locally, and when standing outside the shop window, a picture of the current shop window scene may be taken, and with the help of a touch screen, or alternatively or additionally, with the help of a drawing device, the scene of the shop window 1000 may be set to the desired setting by addressing the parts of the scene that should be highlighted and the parts that may remain in the dark. The desired effect can be achieved by only activating a main light spot and a fill light spot (both indicated by character a) illuminating a specific area on the vertical plane. Therefore, preferred regions of the main light and the light supplement effect should be indicated first. Only the spot light aimed at that specific area is switched on. This may result in some spotlights giving primary light while others give supplementary light to reduce the full shadow of excessive contrast. The spotlight aimed at the unused area is not activated.

Next, as an option, it may be indicated whether and where a backlight effect is required. By the same principle, the spotlight matrix (denoted by character B) mounted in the backlight matrix can cover the entire vertical display plane, but now from the back. For the position of the backlight matrix, please refer to the sectional view. In practice, only a few spot lights will be activated, for example to illuminate the hair from behind, the other spot lights being off.

The same principle is used to achieve the up or beamlet light consistent with backlighting. This is a spotlight (indicated with the character C) which is usually mounted in a position at the bottom in front of the shop window. This is usually a narrow beam spotlight for highlighting special details or making dramatic lighting effects from below. By the same principle, a matrix of LED dots mounted in an upper row light matrix can cover the entire vertical display plane, but now from the front below. For the position of the upward light matrix, please refer to the sectional view.

By means of these three separate matrices, a perfect illumination scene can be achieved, which can maintain main light, fill light, backlight and up-or beamlet illumination. By adding a light sensor or candela meter 211 to the control unit or to the lighting system itself in the shop window, the lighting level or brightness in the displayed shop window can be measured on areas without spotlights. This will enable to reduce the intensity of the spotlight when the daytime lighting level decreases and to keep the contrast constant. Thus, for example, during the day, ambient light levels caused by daylight in the shop window may be measured. For example, when an emphasis factor of five is required, the lighting level on the display should be five times the level of daylight-generated lighting. When the daylight level in the shop window becomes lower than a certain value, the contrast can be maintained by using a lower spot intensity.

Eventually at night (e.g. a level below 20 lux), since the daylight level is close to zero, it will be easy to form 1: emphasis factor of 40 or even higher. This dimming option at night will have a positive impact on both energy consumption and the preferred light balance in the shop window. Next, the system allows for making dynamic scenes by switching or dimming between individual groups of spot lamps. With the possibility of modifying the emphasis factor or by using another set of spot lamps to modify the angle of incidence. Slow gradual transitions between scenes can also be produced in this way. The mutual orientation of the main light, fill light and backlight/beamlet light may be selected to optimize the desired scene setting. For a more realistic/natural and attractive presentation, it is preferred to use two different color temperatures and spotlights with different beam angles aimed from different positions. Like in daytime outdoor conditions, skylight scattered by clouds is generally not directional and is cooler than directional sunlight. To mimic this effect, narrow-beam spotlights with a lower color temperature, i.e. main light lamps mimicking a directed warm sun beam, are usually used from one side. To fill in the (excessively hard) shadow, a wider beam spotlight with a higher color temperature, i.e. a fill light, is used from the other side to imitate cooler stray light or blue sky light. Generally, it is preferable to have the main and supplementary lights come from opposite sides at a horizontal angle of 45 degrees and vertically at an angle of 30 degrees to the vertical direction.

As described above, the method may be performed from a remote location. Generally, images (photographs) are in digitized form, and electronic means of transferring images are well known, such as via the internet, e-mail, wireless data communication systems. Instead of executing the method step by step from a remote location, instructions for a new scene setting may also be collected and sent as a set of instructions to the target shop window. The method also enables monitoring and/or maintaining the status of a specific shop window, upon detecting a failure of an active device of the lighting system, a signal for repairing the system may be created, but alternatively or additionally, settings of other devices of the lighting system may be adjusted from a central, remote location to compensate for the failure of the active device.

Fig. 10 shows a sequence of steps followed to set a desired scene in, for example, a shop window. The method 300 includes the steps of:

-taking 301 an image of a shop window for which a scene is to be set;

-transmitting 303 the image to a remote control station via electronic means;

-performing the step of selecting a scene for the target area;

-selectively turning on/off 305 the lighting units to create a patched lighting pattern;

-evaluating 307 the lighting effect obtained on the identified scene/target area, and

optionally perform

Adjusting 309 the obtained lighting effect through an iterative loop of

steps

305 and 307 until a satisfactory result of the scene setting is obtained.

This sequence of steps may optionally be accomplished via remote control at a remote control station.

Claims

1. An illumination system comprising at least first and at least one second illumination device, each illumination device comprising a first plurality of illumination units mounted only in a first direction along the length of an elongate carrier, each illumination unit being mounted in a respective fixed predetermined orientation, the first plurality of illumination units being configured to directly project a first plurality of spots of light,

wherein the at least first and at least second lighting devices are substantially in a line in the length direction,

wherein the first lighting device has a tunable first light source configured to emit first light of a first color, color temperature or CCT and the second lighting device has a tunable second light source configured to emit second light of a second color, color temperature or CCT different from the first light, and

wherein the first light source is configured to provide a first intensity of first light and the second light source is configured to provide a second intensity of light lower than the first intensity.

2. The lighting system of claim 1, wherein the first light source is configured to increase the intensity of the first light as the intensity of the ambient light increases and decrease the intensity of the first light as the intensity of the ambient light decreases, and the second light source is configured to decrease the intensity of the second light as the intensity of the ambient light increases and increase the intensity of the second light as the intensity of the ambient light decreases.

3. The lighting system according to claim 1 or 2, wherein the number of first light sources is two to twenty times the number of second light sources.

4. The lighting system according to any one of claims 1 to 3, wherein the first light source is configured to project first light in a first direction and the second light source is configured to project second light in a second direction, the second direction being at an angle γ to the first direction, wherein γ is in the range of 10 ° to 160 °.

5. The illumination system of any one of claims 1 to 4, wherein a single spot in a row of light spots comprises both the first light and the second light.

6. The lighting system of any one of claims 1 to 5, wherein the first light source is configured to provide a light beam of a first width and the second light source is configured to provide a light beam of a second width wider than the first width.

7. The lighting system according to any one of the preceding claims 1 to 6, further comprising a third light source in line with the first and further carriers.

8. The lighting system according to claim 7, wherein the third light source is configured to provide third light having a third intensity higher than the first intensity of the first light, preferably higher than the combined intensity of the first and second light.

9. The lighting system according to any one of claims 1 to 6, wherein a third light source is provided on a separate substrate that is not in line with the first and further carriers.

10. The lighting system of claim 9, wherein the third light source is configured to provide backlight, is not arranged in a line, and is configured to emit light substantially in a direction opposite to the emission direction of the first light source, the third intensity being lower than the first intensity.

11. The lighting system of claim 10, wherein the third light source is configured to emit light of a third color different from the first color of the first light.